Torque controlled engine



JuneZS; l1942. s. M. UDALE TQRQUE cNTRoLLED ENGINE.

Filed May 1o, 1940 v '2 sheets-sheet 1 INVENTOK June 23, 1942. s. M.UDALE TORQUE coNTRoLpED ENGINE 2 sheets-sheet? Filed may 1o; 1940zlllllllllflllllllllzl.

Patented June 23, 1942 TORQUE CONTROLLED ENGINE Stanley M. Udale,Detroit, Mich., assigner to George M. Holley and Earl Holley ApplicationMay 10, 1940'Serial No. 334,3294

(ci. 12a-9s) 2 Claims.

The object of this invention is to control the throttle opening, themixture ratio and the spark advance of an airplane engine by means ofthe torque.

Torque indicating devices are now comingvinto common use. These torquedevices obviously indicate the brakeA mean effective pressure.

-As it is well known, these airplane engines are built to develop theirmaximum power at certain altitudes, a few miles above the sea level.Means have to be provided, therefore,'tovprotect them from the effect ofthe dense layer of air found at sea level. It has been found desirablethat'the throttles be gradually opened as the plane ascends to theordinary flying elevations. It has also been found desirable toadvancevthe spark as the air density falls, or to put it the other way,to retard the spark slightly when the abnormally heavy air adjacent tothe sea level is encountered.

Modern airplane engines are always fitted with a supercharger and withconstant speed propellers, and the presence of these devices must be thethrottle I9. The piston u is guided in a cylinder 20 which carries a.compression spring 2|- so that the pressure in the cylinder I3 isbalancedby the compression of the spring 2|. The cylinder 20 carries acollar 22 with which engages a pin 23 projecting from the manuallycontrolled 1 lever 24 which is controlled by the manually controlled rod25. This lever 24 is connected by a one-way connection 4I with the leverI1 and the limit to the opening movement of the lever 24 is determinedby the stop40.

The carburetor is shown) diagrammatically having an anterior throttleI9, a fuel and air I nozzle 35 having a restricted air entrance 36 and arestricted fuel entrance 45 controlled by a y needle valve 46 which inits turn is controlled by.

considered in controlling and 'limiting the maximum torque.

Figure 1 shows diagrammatic'ally an'air cooled radial engine having atorque responsive device.

Figure 2 shows the control means for the carburetor and ignition devicescontrolled by the torque respon'sive means of Figure 1.

Figure 3 shows the carburetor attached to aA conventional engine havinga supercharger and a torque control. e

Figure 4 shows the end view of the torque control. Neither the enginenor the torque control forms any lpart of this invention.

The invention is shown diagrammatically inthe drawings in which a radialaircooled engine is shown diagrammatically at I0 on whichis mounted atorque responsive device II, a supercharger 43 and mixture outlet 44.This engine ID and supercharger 43 are drawn tov a small scale whereasthe rest of the diagram 'is drawn on a large scale.

The torque responsive device II is connected by the pipe I2 with thecylinder I3 in which reciprocates a piston I4 which constitutes a torquecontrol. The torque indicating device corresponds to one of thosedescribed in the S. A. E. Journal for June, 1939, pages 271-276, andspeccally to Figure 4, on page 273,.-and is made. suiiiciently powerfulso that it can operate the piston I4. VThis piston I4 carries acollar-I5 with which engages a pin I6 projecting from a. lever l '|1.This lever I1v is connected by the rod I8 with aneroid bellows 32.lAiloat 3i in a oat chamber 41 subjected to the inlet manifold suctioncontrols the oat mechanism which supplies fuel to the constant levelchamber 41 in order to add extra fuel when the torque reaches itsmaximum.

The piston 33 is shown connected by the pipe 31 with the cylinder I3.This piston 33 carries a needle valve 34 which admits the extrafuel tothe fuel nozzle 35 when the maximum torque is reached. V At the sametime, a one way link 39 rotates the timer'30 to retard the sparkslightly4 when maximum torque is recorded. A one way connection 3Benables the engine to be idle, be-

cause when the levers 24 and I1 are turned 'clockvwise as far aspossible, then the spark is re-V tarded in the well known manner for theobvious purpose of giving a moderately smooth idle. As is well knownthese engines d o not idle in a, satisfactory manner in any event, butthere is some advantage in retarding the spark. A compression spring 42maintains the one way connection 35 connected to the timer 30.

. In Figure 3, the carburetor is shown connected through pipe A44with'the supercharger 50 contained within the housing 43. Thissupercharger is driven by a crank shaft 5l connected with a piston 52which reciprocates in the cylinder 53 having the usual inlet and outletvalves 54 and 55. The spark control rod 38 is shown connected A to thecircuit breaker plate 30 and the circuit breaker itself is shown drivenby the two to one gears 56 and 51. The details of the torque control arecopied from page 273 of the June, 1939, number of the S.- A. E. Journal,Figure 4, and consist of the following: A Y

An internal lgear 58 driven by the crank shaft 5I drives an externalgear 59 which is connected to the diamond-shaped piece 50 which isconnected through the connecting rods 6I and 62 to 2 sans the pistons 63and 6l. A valve admits high pressure oil to the line 66. The pressure inthe pipe 61 is thus automatically maintained equal to that of the torquecreated by the engine. The high pressure oil, the pressure or whichvaries with the torque, is connected through the pipe I2 to theapparatus shown in Figure 2. The propeller take-0B is through the shaft88 which carries the arm 89 upon which are mounted gears 10, 10, whichengage with both the external gear 58 and the internal gear 59. Anytorque that may be applied to the propeller on `the shaft $8 istransmitted through the shaft 88 to the spider 69 which carries thepinion 10. 1f the torque goes up, the pressure in the pipe I2 goes up,and vice versa.

Operation When the manually controlled liever 2t is moved to the left toopen the throttle by coinpressmg the spring 2|. the engine runs with the2@ throttle i8 wide open until the torque responsive device I I createssufficient pressure so as to compress the spring 3i and to close thethrottle I9 into the position determined by the stiiness of the spring2l. if the plane is now flown to the ordinary heights for which theseengines are designed to operate, the throttle i@ will gradually open inorder to maintain a constant torque and this will continue until thethrottle i9 is wide open and thereafter the torque will continually fallas the air density falls in a well lmown manner, until iinally the planecan climb no more,

4throttle i9.

at ordinary levels, say one or two miles, the throttle I9 is closed andthe compression of the spring 2i is reduced and the lever il finds theposition which will develop the desired torque, which torque is reducedslightly as the plane ascends and the spring Zi expands to open the Thishas the desirable advantage that. the maximum power is developed nearthe sea, level and there is a slight drop in power with altitude at allpositions of the throttle, assuming that the plane climbs with axedthrottle. The reverse takes place when constant density is maintained ina supercharger d. It is preferable that the power should fall slightlyrather than rise considerably as the plane is flown to higher altitudes.Excessive power at altitude is of no value.

What I claim is:

l. A torque control for an internal combustion engine having acarburetor, a throttle therefor, a fuel valve therefor, adapted to admitextra fuel to obtain maximum power, an ignition timing device, a torqueindicating device, and means responsive to the torque when the torqueexceeds a predetermined maximum torque for closing the throttle, foradmitting extra fuel and for retarding the timing device.

2. A torque control for an internal combustion engine having a torqueindicating device, a carburetor and a throttle therefor, anautomatically operated throttle lever, a manually controlled throttlelever, spring means interposed between said levers, and means responsiveto the torque for opposing said spring means whereby the manuallycontrolled throttle lever can be set to a given torque and theautomatically controlled throttle lever will open and close the throttleso as to maintain the torque constant at various altitudes.

STANLEY M. UDALE.

